<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>




<style>
    div {
        border: 1px solid black;
        margin: 25px 50px 75px;
        background-color: lightblue;
    }
</style>


<body>
    <h1>简写属性margin-3个值</h1>
    <div>div元素的上外边距是25像素
        左右外边距是50像素
        下外边距是75像素</div>
</body>

</html>